JPS621879A - High-damping composite steel sheet and its production - Google Patents

Abstract

PURPOSE:To develop a high-damping composite steel sheet excellent in press workability as well as rust-preventing property and causing no blister at baking finish by phosphating both sides of steel sheets, removing water of crystallization, putting a viscoelastic substance between the two of the above steel sheets and then carrying out cladding. CONSTITUTION:Phosphating films are formed on the surfaces of galvanized sheets, hot-rolled steel plates, cold-rolled steel sheets, etc., of 0.2-1.6mm thick by >=0.5g/m<2> plating quantity per one side. These steel sheets are heated to 160-220 deg.C to remove water of crystallization in the phosphating films. Then, between the two of the above surface-treated steel sheets, the viscoelastic substance such as ethyleneacrylic acid copolymer resin, modified polyethylene resin, modified polypropylene resin, vinyl acetate resin, etc., is provided as vibration-damping material in 0.03-0.6mm thickness, which is subjected to forced cladding to form the high-damping composite steel sheet having superior characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration-damping composite steel plate that has excellent rust prevention properties and press workability and does not blister during baking painting, and a method for manufacturing the same.

[Conventional technology]

To prevent vibrations generated from structural members or other members of various machinery, vehicles, ships, etc., it is necessary to modify the installation foundation, thicken the member itself, apply vibration damping material, or Countermeasures have been taken, such as spraying or coating with a polymer solution that exhibits a vibration damping function. Particularly in recent years, regulations on noise generated by vehicles, etc. in cities have been strengthened, and as a countermeasure, there has been a trend to make vehicle components from materials that have a vibration damping function. A composite material arranged in layers has been developed. (Unexamined Japanese Patent Publication No. 59-57743, No. 5
9-146840) This type of vibration-damping composite steel plate has a thickness of 1 m and (1 m), respectively.
For example, the thickness between two steel plates up to about 0.1 mm to 0.
．． It is made by laminating six layers of viscoelastic material such as plastic, and with this structure, the vibration energy applied to it is rapidly converted into thermal energy through plastic deformation of the viscoelastic material layer. The purpose is to demonstrate the function of effectively damping vibrations.

By the way, when comparing the vibration damping function of vibration-damping composite steel plates in terms of reverberation time, it takes 500 seconds for the vibrations of ordinary steel plates to dampen and reach a certain value, while that of vibration-damping composite steel plates takes about 1 second. .

[Problem that the invention seeks to solve]

By the way, as long as this vibration-damping composite steel plate is simply used as a plate material, it exhibits a sliding effect without any inconvenience. Baking paint at high temperatures can cause various problems.

Describe below an example of forming a damping composite steel plate into a pressed product. First, as a result of initially using an untreated steel plate as the raw steel plate used for vibration-damping composite steel plates, rust developed on the contact surface between the steel plate and the viscoelastic substance during the practical stage, and there was a risk that the adhesive surface would peel off. .

To avoid this, we decided to use a phosphate-treated steel sheet to improve the adhesion of the electrogalvanized top coat as the raw steel sheet. As a result, rusting on the adhesive surface between the steel plate and the viscoelastic material layer was prevented by 11%. but,
Paint baking after press working is a process (180℃, 20 minutes)
In this case, a flaking phenomenon occurred and the adhesive surface peeled off.

It was thought that the cause of this was due to the phosphate treatment of the steel sheet as described above, so we decided to limit the surface treatment of the raw steel sheet to electrogalvanization only and use a steel sheet without phosphate treatment as the raw steel sheet. did. However, as a result of this, the occurrence of cracking increased during the press working, and the cracking rate reached over 50%, so this was also found to be a failure.

As a result of the series of experiments described above, we found that with regard to the use of conventional vibration-damping composite steel plates as materials for press-formed products, etc.
It has become clear that there are some problems as mentioned above.

The present invention was made in order to solve the above-mentioned problems of conventional vibration-damping composite steel sheets, and provides a vibration-damping composite steel sheet and its manufacturing method that can be used for highly processed products such as pressed products. This is what we are trying to provide.

[Means for solving problems]

Based on the above series of experimental results, we continued with some further tests.

First, in order to investigate the cause of the flaking phenomenon that occurred when a phosphate-treated film was used, electrolytic galvanizing (4 g) was applied to both sides.
/rn') and phosphate treatment (2g/rn').
) The steel plate that has been subjected to
°C, 180 °C, 200 °C, and 220 °C, held at each temperature for 3 minutes, and then cooled. A viscoelastic material layer was sandwiched between each two steel plates to form a vibration-damping composite steel plate test piece. Manufactured.

Next, the above composite steel plate test piece was heated at 200°C for 20 minutes in an electric furnace.
Leave it for a minute and measure the condition of bags that appear on the test piece.
Furthermore, the residual moisture content of the heat-treated steel plate was measured. The condition of the bag is expressed as ΔtIIIll, which is expressed by the following formula, and the residual moisture content is expressed as rng/m.

ΔL=thickness of test piece after heat treatment−thickness of test piece before heat treatment The results of the experiment are shown in FIGS. 1 and 2. FIG. 1 is a diagram showing the relationship between heating temperature and residual moisture content, and FIG. 2 is a diagram showing the relationship between heating holding time and residual moisture content. However, regarding the latter, tests were conducted at typical heating temperatures. In addition, Table 1 summarizes the results of the above tests, but the heating holding time in the table is uniformly 3 minutes because the typical heating temperature of 120°C is shown in Figure 2.
This is because it has been found that the influence of the heating holding time on the residual moisture content at 160° C. and 1 minute or more, especially 3 minutes, results in a stable value.

In general, the blistering phenomenon does not pose a practical problem if the thickness Δt is 10 μm or less. Therefore, as shown in Figure 1 and Table 1, the heating temperature is preferably 160°C or higher (it is necessary to set it to 180°C or higher. As shown in the figure, the residual moisture content is lower than 220°C). Since the temperature remains almost constant, no increase in effectiveness can be expected even if the temperature is heated further.

The next test conducted was to examine the relationship between the weight of the phosphate film and the press formability of the III-thickness composite steel sheet. In other words, both sides of a 0.711I11 steel plate are electrogalvanized, and the area weight (one side) is set to θ~10 on both sides.
Phosphate treatment was performed varying up to 2 g/m',
The side of the electrogalvanized layer is adhered to the viscoelastic material layer to produce a damping composite steel plate as described above, and a disk-shaped test blank corresponding to the above-mentioned phosphate coating weight is made from the composite steel plate. Formed. This blank was put on the press test machine shown in FIG. 3 to conduct a test to see the relationship between the basis weight of the phosphate film and workability. In Figure 3, (1) is a punch with a diameter of 100 mm, (2) is a chair with a diameter of 103.5 mm, (3) is a test blank, and 1 (Iζ is the circular arc around the periphery of the punch (1). 5 mark in radius, I (2 is 2.5+ in same radius of die (2)
nm.

The wrinkle suppressing force P is 35 tons.

The diameter of the test blank (3) is gradually increased under the above press conditions, and the maximum blank diameter that can be formed without breaking is determined. It is determined that the larger the maximum blank diameter, the better the formability.

FIG. 4 is a diagram showing the relationship between the basis weight of the phosphate film and the maximum moldable blank diameter. As shown in the figure, if the basis weight of the phosphate film is 0.2g/r or less, it is the same as that without phosphate treatment, and is 0.2g/rn”~0.5g/r.
At r+F, the effect of the phosphate film can be seen to some extent, but there are many variations. However, it can be seen that the formability is greatly improved and stable when the paper sheet is 0.5 g/m" or more compared to the case where no phosphate treatment is applied. The area weight of the phosphate film is usually 1-c. -5g/m is often used.

Based on the findings from the above experiments, the present inventors conducted extensive studies and arrived at the present invention. That is, the present invention provides: (1) A vibration-damping steel plate having a viscoelastic substance layer sandwiched between two steel plates, wherein both sides of the steel plate have a basis weight (one side) of 0.
(2) A damping composite steel plate that has been treated with phosphate to a concentration of 5 g/m or more and has a phosphate film that has removed crystal water on at least the west side that is in contact with the viscoelastic material layer, and (2) phosphate treated on both sides. After that, a viscoelastic material layer is sandwiched and crimped between two steel plates that have been heated to 160 to 220°C to remove crystallized water in the phosphate coating. .

[Effect]

The damping composite steel sheet according to the present invention has a phosphate film on the outer surface, and the surface of the steel sheet that is bonded to the viscoelastic material layer has a phosphate film that does not contain heat-treated crystallization water. Therefore, the above-mentioned composite steel sheet has excellent vibration damping properties, anticorrosion properties, and press workability, and also has an excellent function of not causing blisters even when heated during baking and painting.

[Embodiments of the invention]

A cold-rolled steel sheet with a thickness of 0.7 m, which had been electrolytically galvanized on both sides with a coating weight of 4 g/m'' and phosphate treated with a coating weight (one side) of 2 g/rn', was heated to 180°C. rear,
O, 1m thick ethylene acrylic acid copolymer system 4MHr
A damping composite steel plate is produced by laminating with i.

As a result of forming an oil pan using the vibration-damping composite steel plate mentioned above, as shown in Table 2, the bonding surface between the steel plate and the viscoelastic material layer We were able to manufacture a satisfactory oil pan by solving all the problems such as rusting, cracking during press working, and blistering during baking painting after press working.

This is achieved by electrogalvanizing the adhesive surface of the steel sheet with the resin to prevent rust, improving press workability by treating both sides of the vibration-damping composite steel sheet with phosphate, and This is thought to be due to measures such as preventing blistering of the resin layer by heating the steel plate after salt treatment and removing crystal water in the phosphate treatment film.

In addition to the electrogalvanized steel sheets used in the above embodiments, the steel sheets of the present invention include hot-rolled steel sheets, cold-rolled steel sheets, hot-dip galvanized steel sheets, alloyed steel sheets, zinc-based plated steel sheets (zinc iron, etc.), and the like. It refers to

The thickness of the steel plate also varies from 0.2mg+ to 1. (Things up to in++m are used.

Furthermore, the viscoelastic material used as the vibration wJ damping material is
Ethylene 7' acrylic acid copolymer resin, modified polyethylene resin, modified polypropylene mIIθ, vinyl acetate resin, etc. can be used, and the thickness is 0.03 mm.
It can be used up to 0.6 order.

〔Effect of the invention〕

In the production of the vibration-damping composite steel sheet of the present invention, a steel sheet that has been subjected to phosphate treatment and then heated to remove the water of crystallization in the lyphosphate film is used. ,
As shown in Table 2, it has excellent corrosion resistance and workability, does not cause blisters even when baked after processing and forming, and has excellent vibration damping properties (loss coefficient) ffIax of 0.1 or more. It has excellent performance.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between the heating temperature of the steel plate and the residual moisture content in the test of damping composite steel plates, Figure 2 is the diagram showing the relationship between the heating holding time and the residual moisture content, and Figure 3 is the diagram showing the relationship between the heating holding time and the residual moisture content. FIG. 4, which is a sectional view of the press testing machine, is a diagram showing the relationship between the basis weight of the phosphate film and the maximum moldable blank diameter. Agent: Masaru Sato, Patent Attorney 2018 standard amount of nitrogen (mg/m2)

Claims (2)

[Claims] (1) Use a steel plate that has been treated with phosphate with a basis weight (one side) of 0.5 g/m^2 or more on both sides, and has a phosphate film from which water of crystallization has been removed at least on the surface in contact with the viscoelastic substance. A vibration-damping composite steel plate characterized by having a layer of viscoelastic material sandwiched between the two. (2) Phosphate treatment is performed on both sides of the steel plate, and the steel plate is
A vibration-damping composite steel plate is produced by heating the steel plate to 0 to 220°C to remove crystallized water in the phosphate film, and then sandwiching and pressing a viscoelastic substance between the two steel plates. A method of manufacturing a vibration-damping composite steel plate.